Fix firstmedia.com schedule mislead.

The retrieved schedules from firstmedia.com api indeed confusing. Taken for example
the following snippet:

```json
{
  channelNo: '245',
  title: 'News Bulletin',
  date: '2023-11-07 17:00:00',
  startTime: '2023-11-07 17:00:00',
  endTime: '2023-11-07 17:30:00',
  description: 'News Bulletin',
  long_description: 'Hourly update of international news with an emphasis on the Arab world.'
}
```

Neither `startTime` nor `endTime` is an actual time but an offset from `date`.
If its an actual time then it would overlap with each others.

The workaround is to calculate the start and stop time offset, sort the schedules
based on those offset, and last skip overlapped schedules.

Signed-off-by: Toha <tohenk@yahoo.com>

sites/firstmedia.com/firstmedia.com.config.js

@@ -7,24 +7,36 @@ dayjs.extend(utc)
 
 module.exports = {
   site: 'firstmedia.com',
-  days: 1,
-  url: function ({ channel, date }) {
+  days: 2,
+  url({ channel, date }) {
     return `https://api.firstmedia.com/api/content/tv-guide/list?date=${date.format('DD/MM/YYYY')}&channel=${
       channel.site_id
     }&startTime=0&endTime=24`
   },
-  parser: function ({ content, channel }) {
+  parser({ content, channel, date }) {
     if (!content || !channel) return []
 
-    let programs = []
+    const programs = []
     const items = parseItems(content, channel.site_id)
-    items.forEach(item => {
-      programs.push({
-        title: parseTitle(item),
-        description: parseDescription(item),
-        start: parseStart(item).toISOString(),
-        stop: parseStop(item).toISOString()
+      .map(item => {
+        item.start = toDelta(item.date, item.startTime)
+        item.stop = toDelta(item.date, item.endTime)
+        return item
       })
+      .sort((a, b) => a.start - b.start)
+
+    const dt = date.tz('Asia/Jakarta').startOf('d')
+    let lastStop
+    items.forEach(item => {
+      if (lastStop === undefined || item.start >= lastStop) {
+        lastStop = item.stop
+        programs.push({
+          title: parseTitle(item),
+          description: parseDescription(item),
+          start: asDate(parseStart({ item, date: dt })),
+          stop: asDate(parseStop({ item, date: dt }))
+        })
+      }
     })
 
     return programs
@@ -66,10 +78,22 @@ function parseDescription(item) {
   return item.long_description
 }
 
-function parseStart(item) {
-  return dayjs.tz(item.startTime, 'YYYY-MM-DD HH:mm:ss', 'Asia/Jakarta')
+function parseStart({ item, date }) {
+  return date.add(item.start, 'ms')
 }
 
-function parseStop(item) {
-  return dayjs.tz(item.endTime, 'YYYY-MM-DD HH:mm:ss', 'Asia/Jakarta')
+function parseStop({ item, date }) {
+  return date.add(item.stop, 'ms')
+}
+
+function toDelta(from, to) {
+  return toDate(to).diff(toDate(from), 'milliseconds')
+}
+
+function toDate(date) {
+  return dayjs(date, 'YYYY-MM-DD HH:mm:ss')
+}
+
+function asDate(date) {
+  return date.toISOString()
 }